1. 使用export * 的时候，打开transform-runtime时，babel转换出来的模块会引入import

可以看这个issues, https://github.com/babel/babel/issues/2877 (这个bug继续用webpack，转在混合了import和commonjs下，会导致exports报错，可看这里)

输入

export * from './str';
//import a from 'a.js'
//..........

输出

//这里引入了import
import _Object$defineProperty from 'babel-runtime/core-js/object/define-property';
import _Object$keys from 'babel-runtime/core-js/object/keys';
Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.uniqueCommentDetail = exports.uniqArray = exports.getUrlParams = undefined;


var _str = require('./str');
//这里去输出export * 
_Object$keys(_str).forEach(function (key) {
    if (key === "default" || key === "__esModule") return;

    _Object$defineProperty(exports, key, {
        enumerable: true,
        get: function get() {
            return _str[key];
        }
    });
});

//...............后面省略